Weighing instrument



Sept. 18, 1923. 1,468,129

R. G. AlNswoRTH wmenme INSTRUMENT Filed Aug. 2s, 1919 2 sheets-sheet 1 INVENTOR. R G AlNwoRrH y "5 I ATTORNEY.

Sept. 18, 1923. 1,468,129

R. G. ANSWQRTH wEIGHING INSTRUMENT Filed Aug`. 26

1919 2 Shouts-Sheet 2 K INVENTOR. 6. A/Nswonm ATTORNEY.

Patented Sept. 18, 1923.

PATENT OFFICE.

ROBERT G. AAINSWORTH, F DENVER, COLORADO.

WEIGHING INSTRUMENT.

, Applicatin filed August 26, 1919. Serial No. 319,920.

` To all whom it may concern:

Be it known that I, Ronnm (`r. ATNS- woirrn, ay citizen of the United States, residing at Denver, in the county ofDcnver and State of Colorado, have invented certain new and useful Improvements in Weighing Instruments, of which the vfollowing is a specification. f

This invention relates to precision weighing instrui'nents and its primary object is to provide in a balance of the type used by chemists and assayers, a vernier appliance of novel construction for the purpose of indicating the weight of a load in fractions of the Sub-divisions of a fixed scale or graduated system of Standard units of weight.

An embodiment of my invention has been shown in the accompanying drawings in the various views of which like parts are similarly designated, and in which- Figure 1 represents a front elevation of a balance of conventional construction to which my invention is applied, the weighing mechanism being as usual enclosed in a dustproof casing; 1

Figure 2, a partially sectional elevation of the Vernier attachment drawn to an enlargedscale; i

Figure 3, a further enlarged section taken on the line 3 3, Figure 1;

Figure 4, an enlarged sectional elevation of the bearings ill the side of the case of theH instrument in which the rider-carrier rod and the Vernier rod of the appliance are supported, and

Figure 5, an enlarged section taken on the line 55, Figure 2.

Referring to the drawings by numeral. reference characters, 2 designates a base plateA preferably made of glass which constitutes the bottom of a dust-proof casing 3 in which the operating mechanism of the balance is enclosed.

The beam 4 of the instrument is Supported through the medium of a knife-edge 5 upon a forwardly extending agate bearing G at the upper end of a column 7 rwhich is fixed upon the base plate 2. i

The hangers 8 which support the pans 9 of the instrument are suspended from the ends of the beam through the medium of stirrups 10, a releasing yoke 12 at the upper end of a rod extending through the column, is operatively connected with an operating rod 13 beneath the case to lift the beam and the stirrups ofi' their bearings when the instrument is not in operation, and a. pan-y arrest which. likewise is controlled bythe operating rod is provided to arrest the motion of the hangers.

A downwardly extending pointer 14 on the beam cooperates with a fixed scale 15 on the base of the column t0 indicate the position. of the beam with relation to the horizontal. I

A beveled Straight edge 1G on the beam provides a sliding support for a V-shaped rider 17 which cooperates with a graduated carrier rod 18 to indicate in fractions of measuring units, the weight of a load upon one of the pans of the balance.

The carrier rod has a combined rotary and lengthwise sliding movement in a bearing in a 'wall 34 of the dust-proof casing, and a therewith alined bearing in a post 19 erected upon the cap 2() which covers the upper end of the column, and it has a. laterally extending arm 21 provided with a hook-shaped extremity 22 which adapts .it to lift the rider oif the beam and carry it to any other point thereof.

The bearing in the post 19 is Slotted to permit of the passage of this arm and the bearing in the side of the casing is constructed to oppose a lengthwise movement of the rod while it is being rota-ted to place the rider on the straight edge of the beam.

The bearing consists to this end, as is best Shown in Figure 11 of the drawings, of a bushing 23 which is tapped in an opening in the wall of the casing and projects beyond the ends thereof.

A head 24 at one end of the bushing vbears upon a coverp.late 25 placed against the Side of the wall and a hollow nut 26 is screwed upon the opposite threaded end of the bushing against a similar plate 27 placed against the opposite side of the wall.

A second bushing 28 loosely fitted in the other engages at one of its ends with a springwasher 29 within the nut'and it has a feather 30 which extends into a correspondingly formed groove in the portion of the carrier rod extending through the bearing.

It will be seen that when the carrier rod is turned to raise or drop the rider, the feather will bind against a side 0f the slot in the fin bushing which by trictional engagement with the spring-washer opposes rotation ot' the rod.

It follows that the carrier-rod while being rotated trictionally held against lengthwise motion and thereby permits ot the rider being` placed upon the straight-edge ot the beam at the exact point to which it has been carried by adjustment ot the rod.

A vernier ll lixed at the end oit a rod extending above the carrier rod in.parallel relation thereto, overlaps the graduated portion oit the carrier-rod so that the graduations ot its scale, extended t0 its lower edge, may register with the graduations ot the other scale.

The vernier rod is slidably mounted in bearings on the betoreanentioned post and the wall ot the casii'ig. It is held against rotation by a screw 35 on the post which projects into a longitudinal slot ot' the rod and its end remote trom that at which the vernier is applied, is threaded for the applicat-ion ot an adjusting nut 33 which bears upon the outside ot the wall.

A spring 236 coiled around the rod between a collar 3T and a bearing plate on the side of the wall opposite t0 that engaged by the nut, yieldingly opposes lengthwise movement ot the rod when the nut is advanced upon its threaded end, and by subsequent expansion causes the rod to automatically more in the opposite direction when the movement oi the nut reversed.

The rotary motion ot the rider-carrying rod is limited by two stops 3S on a collar 39 which extend at opposite sides ot the vernier rod.

The V-shaped rider is used in the operation oli the instrument tor balancing as well as tor weighing', the side ot the beam at which it is normally positioned being ont of balance to the extent ot its weight.

The scale Ll0 on the carrier rod is divided into equal spaces representing standard units ot measurement (prete ably milligrams) and the. vernier scale divides the spaces into fractions (preferably tenths of a milligram) In the operation ot the instrument. after the weighing mechanism has been released by the adjustnieut ot the yoke and the pan arrest through the medium ot the operating rod, the rider is moved along the beam by adjustment ot the carrier rod until the beam is in balance. the exact balancing position being indicated by the position ot the pointer l-i on the beam with relation to the zero point ot the index l5 on the base of the column.

After the scale has thus been brought to a condition ot equilibrium. thevernier is moved b v adjustment or the `nut upon the threaded end ot its rod until its zero point coincides with that ot the scale on the earrier rod after which the load is placed on one of the pans ot the instrument and the other pan is weighted to balance the load to a Ytraction within the measuring capacity oi" the vernier scale.

The rider is now moved along the straight edge of the beam by adjust-ment ot the carrier-rod until a perfect balance is ettected when the graduation ot' the carrier scale nearest the zero point ot the vernier shows the weight in n'iilligrams or other measuringr units and the Vernier itselt shows the tractions thereof.

Having thus described my inrention what I claim and desire to secure by Letters Patent is:

1. In a balance ot the character described, a tulerumed beam having a straight-edge. a rider movably supported thereon, a sliding member adapted to shift the rider and bearing a graduated scale, and an indicatory element cooperating with said scale, and having a lengthwise adjustment with relation thereto.

Q. In a balance of the character described, a ulcrumed beam having a straight-edge, a rider movably supported thereon, a sliding member adapted to shi'lit the rider and bearing a graduated scale, and a Vernier cooperating with said scale and having a lengthwise adjustment with relation thereto.

3. In a balance oit the character described, a tulcrumed. beam having a straight-edge, a rider movably supported thereon, a sliding member adapted to shi'lt the rider and bearing a graduated scale, a Vernier cooperating with said scale, a threaded rod supporting the vernier, a bearing tor said rod, a nut on the rod for its longitudinal movement in one direction, and a return-spring yieldingly opposing said movement.

4i. In a balance oit the character described, a tulcrumed beam having a straight-edge, a rider movably supported thereon, a sliding member adapted to shiit the rider and bearing a graduated scale, a Vernier cooperating with said scale, a threaded rod supporting the vernier, a bearing 'for said rod, a nut on the rod at an end of said bearing, to move the rod longitudinally in one direction, and a spring attached to the rod at the opposite end oi the bearing to yieldingly oppose said movement.

In a balance ot the character described` a 'tulcrumed beam having a straight-edge, a rider movably supported thereon, a rotary and lengthwise movable carrier-rod having an arm to raise and drop the rider and bearing a graduated scale. a bearing for the rod including a bushing, a spring washer at an A end thereof, and a second bushing inside of the other, engaging the washer and. having a groove-and-feather connection with the rod. and an indicatory element cooperating wit-h the scale.

loo

6. In a balance of the character described, a fulcrumed beam having a straight-edge, a rider movably supported thereon, a rotary and lengthwise movable carrier-rod having an arm to raise and drop the rider and bearing a graduated scale, a bearing for the rod, including a bushing, a nut screwed at an end thereof, a spring-washer engaging the nut, and a second bushing inside the other, engaging the washer and having a grooveandfeather connection with the rod, and an indicatory clement cooperating with the scale.

7. In a balance of the character described, a beam having a straight-edge, a column for the support of the beam, a rider movably supported on the beam, a rotary and lengthwise movable carrier rod having an arm to raise and drop the rider, and a post on the column having a bearing for the rod, which is slotted for the passage of the arm.

k8. In a balance of the character described, a fulcrumed beam having a straight edge, a rider, a moving member adapted to shift the rider on the straight edge, and two cooperating scales one of which moves with said member and the other of which is relatively adjustable.

9. In a balance of the rcharacter described, a fulcrumed beam having a straight edge, a rider, a rotary and lengthwise movable member to shift the rider on the straight edge, and resilient friction-means resisting longitudinal displacement of the member during its rotation.

y 10. In a balance of the character described, a fulcrumed beam having a straight. edge, a Veshaped rider slidably supported thereon, and a rotary and lengthwise movable carrier-rod having a V-shaped arm adapted to engage at its crotch, the crotch of the rider at its point of Contact with the beam, whereby said rider may be raised and lowered and carried to any part of the beam without lateral or rotary displacement.

In testimony whereof I have affixed my signature. Y

ROBERT G. AINSWORTH. 

